In horology, the manufacture of small display, hand-fitting or external components always poses practical problems of production, owing to the importance of these components in the aesthetical aspect of a watch and how it is evaluated by the client or user.
Indeed, the user's gaze is necessarily drawn to these components, which must therefore have a flawless appearance, a very fine but also very regular surface finish, and, generally, brightness and reflection qualities that are difficult to obtain in a reproducible manner. Indeed, components such as appliques are distributed in large numbers over the watch dial, and must be perfectly identical.
The production cost and the weight of these components must also be kept under control, especially when they are mobile, like hands. Consequently, convenient solutions consisting, in luxury horology, of machining the components in a precious alloy weight, like gold, are not always the most suitable.
It is also known that manufacturing such components with prior machining followed by a surface treatment generates a relatively high scrap rate, since the treatment reveals visual and/or surface defects that were not visible at the machining stage, and is therefore wasted, when it is expensive because of the desired finish.
DE Patent Application 2034006A1 in the name of MELTER & KUEHN discloses a method for producing markings on dials. The markings are formed in relief from the back to the front of the dial. The hollows in the back portion are filled with a visually contrasting filler material, such as paint, plastic, low-temperature molten metal, or similar. Then the protruding areas of the front portion are milled until the contrasting filler appears.